以兔眼蓝浆果(Vaccinium ashei Reade)品种‘粉蓝’(‘Powderblue’)和‘园蓝’(‘Gardenblue’)2 年生扦插苗为研究对象,对经干旱或淹水胁迫处理14 d 后以及恢复正常水分供应后幼苗的生长指标及光合特性变化进行了分析和比较。结果显示:干旱或淹水胁迫处理14 d,2 个品种幼苗的生长均受到严重抑制,根系干质量、茎叶干质量、幼苗的相对生长速率以及叶片净光合速率、气孔导度、胞间CO2 浓度和蒸腾速率均显著低于对照;而根冠比和气孔限制值则基本上高于对照,且气孔限制值与对照有显著差异。恢复正常水分供应60 d 后,2 个品种的根系干质量和茎叶干质量仍低于对照、相对生长速率接近或高于对照、根冠比均高于对照。干旱或淹水胁迫处理7 和14 d,2 个品种叶片的叶绿素含量指数(CCI)、PSⅡ最大光化学效率(Fv / Fm )、PSⅡ有效光量子产量[Y(Ⅱ)]总体上低于对照;干旱胁迫解除后2 个品种叶片的CCI 值和Fv / Fm值迅速恢复至对照水平,但在淹水胁迫解除7 d 后它们的CCI值和Fv / Fm值仍保持下降趋势,至淹水胁迫解除14 d 后恢复至对照水平;2 个品种叶片的Y(Ⅱ)值在干旱或淹水胁迫解除7 d 后仍持续降低,至干旱和淹水胁迫解除14 d 后基本恢复至对照水平。综合比较结果表明:干旱或淹水胁迫对兔眼蓝浆果品种‘粉蓝’和‘园蓝’的生长及光合特性均有一定的抑制作用且淹水胁迫的抑制作用较强,但这种抑制作用具有可逆性,在干旱或淹水胁迫解除后二者的生长和光合特性均不同程度恢复。另外,水分胁迫条件下导致2 个品种光合能力下降的主导因素是气孔限制因子。

Taking two-year-old cutting seedlings of cultivar ‘Powderblue’and ‘Gardenblue’of rabbiteye blueberry (Vaccinium ashei Reade) as research objects, changes in growth indexes and photosynthetic characteristics of seedlings after drought or flooding stressed for 14 d and recovering normal water supplying were analyzed and compared. The results show that after drought or flooding stressed for 14 d, growths of two cultivar seedlings are inhibited severely, and their dry weight of root, dry weight of stem and leaf, seedling relative growth rate and net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate of leaf all are significantly lower than those of the control, while root/ shoot ratio and stomatal limitation value are basically higher than those of the control and there is a significant difference in stomatal limitation value between treatment group and the control. After recovering normal water supplying for 60 d, dry weight of root and dry weight of stem and leaf of two cultivars are still lower than those of the control, relative growth rate is close to or higher than that of the control, and root/ shoot ratio is higher than that of the control. After drought or flooding stressed for 7 and 14 d, chlorophyll content index (CCI), the maximal photochemical efficiency of PSⅡ(Fv / Fm ) and effective quantum yield of PSⅡ[Y(Ⅱ)]of leaf of two cultivars are generally lower than those of the control. After releasing of drought stress, CCI value and Fv / Fm value of leaf of two cultivars quickly recover to the control level, while after releasing of flooding stress for 7 d, their CCI value and Fv / Fm value are still decreased continuously, and recover to the control level until releasing of flooding stress for 14 d. After releasing of drought or flooding stress for 7 d, Y(Ⅱ) value of leaf of two cultivars is still decreased continuously, and recover to the control level after releasing of drought or flooding stress for 14 d. The comprehensive comparison result shows that drought or flooding stress has a certain inhibition effect on growth and photosynthetic characteristics of cultivar ‘Powderblue’and ‘Gardenblue’of V. ashei and the inhibition effect of flooding stress is stronger, but the inhibition effect is reversible, and their growth and photosynthetic characteristics are recovered at different degrees after releasing of drought or flooding stress. Moreover, stomatal limitation factor is the dominant factor leading to photosynthetic capacity decreasing of two cultivars under water stress condition.